About Your Md Series Storage Array; Physical Disks, Virtual Disks, And Disk Groups; Physical Disks; Physical Disk States - Dell PowerVault MD Series Administrator's Manual

About Your MD Series Storage Array

This chapter describes the storage array concepts, which help in configuring and operating the Dell MD Series storage
arrays.

Physical Disks, Virtual Disks, And Disk Groups

Physical disks in your storage array provide the physical storage capacity for your data. Before you can begin writing
data to the storage array, you must configure the physical storage capacity into logical components, called disk groups
and virtual disks.
A disk group is a set of physical disks upon which multiple virtual disks are created. The maximum number of physical
disks supported in a disk group is 96 disks for RAID 0, RAID 1, and RAID 10, and 30 drives for RAID 5 and RAID 6. You can
create disk groups from unconfigured capacity on your storage array.
A virtual disk is a partition in a disk group that is made up of contiguous data segments of the physical disks in the disk
group. A virtual disk consists of data segments from all physical disks in the disk group.
All virtual disks in a disk group support the same RAID level. The storage array supports up to 255 virtual disks (minimum
size of 10 MB each) that can be assigned to host servers. Each virtual disk is assigned a Logical Unit Number (LUN) that
is recognized by the host operating system.
Virtual disks and disk groups are set up according to how you plan to organize your data. For example, you can have one
virtual disk for inventory, a second virtual disk for financial and tax information, and so on.

Physical Disks

Only Dell supported physical disks are supported in the storage array. If the storage array detects unsupported physical
disks, it marks the disk as unsupported and the physical disk becomes unavailable for all operations.
For the list of supported physical disks, see the Support Matrix at dell.com/support/manuals.

Physical Disk States

The following describes the various states of the physical disk, which are recognized by the storage array and reported
in the MD Storage Manager.
Status Mode
Optimal Assigned
Optimal Unassigned
Optimal Hot Spare Standby
Description
The physical disk in the indicated slot is configured as
part of a disk group.
The physical disk in the indicated slot is unused and
available to be configured.
The physical disk in the indicated slot is configured as a
hot spare.
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